1. Field of the Invention
The present invention relates to a cushion used for seats in vehicles such as automobiles or aircraft and to a method of manufacturing such a cushion.
2. Description of the Prior Art
Various materials are used for conventional cushions for seats used in vehicles such as automobiles or aircraft. Examples of such materials include palmrock, using palm fibers, a synthetic resin foam such as a polyurethane foam, or a cotton-like material of organic synthetic fibers.
Palmrock, however, has a large specific gravity and easily collapses.
Polyurethane foam has poor air permeability and cannot provide a comfortable cushion. High-resiliency polyurethane foams considered to provide more comfort have larger specific gravities than flexible polyurethane foams.
A cotton-like material consisting of organic synthetic fibers easily collapses, so it is not suitable for use in a cushion either.